阅读说明：本技术 一种碳碳双键桥接的手性多孔有机聚合物的制备方法 (Preparation method of carbon-carbon double bond bridged chiral porous organic polymer ) 是由 李秋艳 刘洋 吴邦 李长云 王晓军 于 2021-07-19 设计创作，主要内容包括：本发明专利公开了一种碳碳双键桥接的手性多孔有机聚合物的制备方法,包括以下步骤：将以式(1)所示的有机配体和2,4,6-三氰基-1,3,5-三甲基苯依次加入到盛有N,N-二甲基甲酰胺的高压反应釜中溶解得到反应溶液；再向反应溶液中加入哌啶,溶解后于90-180℃温度下反应48-120小时,反应结束后冷却至室温,将反应物料进行离心,收集沉淀；将沉淀用甲醇、丙酮和二氯甲烷分别洗涤三遍,得到的黄色粉末即为碳碳双键桥接的手性多孔有机聚合物。该方法简单易操作,且制备出的手性多孔有机聚合物一方面可具有更高的化学稳定性和热稳定性,另一方面还具有更好的共轭性和电子离域性。(The invention discloses a preparation method of a carbon-carbon double bond bridged chiral porous organic polymer, which comprises the following steps: sequentially adding an organic ligand shown in a formula (1) and 2,4, 6-tricyano-1, 3, 5-trimethylbenzene into a high-pressure reaction kettle containing N, N-dimethylformamide to dissolve to obtain a reaction solution; adding piperidine into the reaction solution, dissolving, reacting at 90-180 ℃ for 48-120 hours, cooling to room temperature after the reaction is finished, centrifuging the reaction material, and collecting precipitate; and washing the precipitate with methanol, acetone and dichloromethane for three times respectively to obtain yellow powder, namely the carbon-carbon double bond bridged chiral porous organic polymer. The method is simple and easy to operate, and the prepared chiral porous organic polymer has higher chemical stability and thermal stability on one hand, and also has better conjugation property and electron delocalization on the other hand.)

1. A preparation method of a carbon-carbon double bond bridged chiral porous organic polymer is characterized by comprising the following steps:

a. synthesis of organic ligands: the organic ligand is (S) -4,4' - (2- (pyrrolidine-2-yl) -1H-benzo [ d ] imidazole-4, 7-diyl) benzaldehyde shown as a formula (1);

b. sequentially adding an organic ligand and 2,4, 6-tricyano-1, 3, 5-trimethylbenzene into a high-pressure reaction kettle containing N, N-dimethylformamide to dissolve to obtain a reaction solution; the mass ratio between the organic ligand and 2,4, 6-tricyano-1, 3, 5-trimethylbenzene is (1-2): 1; the adding amount of the N, N-dimethylformamide is 10-20mL/mmol2,4, 6-tricyano-1, 3, 5-trimethylbenzene;

c. adding piperidine into the reaction solution, dissolving, reacting at 90-180 ℃ for 48-120h, cooling to room temperature after the reaction is finished, centrifuging the reaction material, and collecting precipitate; the mass ratio between piperidine and 2,4, 6-tricyano-1, 3, 5-trimethylbenzene is (3-15): 1;

d. and c, washing the precipitate collected in the step c with methanol, acetone and dichloromethane respectively for three times to obtain yellow powder, namely the carbon-carbon double bond bridged chiral porous organic polymer.

2. The method for preparing a carbon-carbon double bond bridged chiral porous organic polymer according to claim 1, wherein in the step b, the mass ratio of the organic ligand to the 2,4, 6-tricyano-1, 3, 5-trimethylbenzene is 1.5: 1; the amount of N, N-dimethylformamide added was 15mL/mmol2,4, 6-tricyano-1, 3, 5-trimethylbenzene.

3. The method for preparing a carbon-carbon double bond bridged chiral porous organic polymer according to claim 1 or 2, wherein in step c, after dissolution, the reaction is carried out at 150 ℃ for 72h, and the mass ratio of piperidine to 2,4, 6-tricyano-1, 3, 5-trimethylbenzene is 6: 1.

4. the method for preparing the carbon-carbon double bond bridged chiral porous organic polymer according to claim 1 or 2, wherein the specific steps for synthesizing the organic ligand are as follows:

a. weighing cesium carbonate and cesium fluoride in a reaction bottle, adding water to dissolve, adding toluene, removing air in the reaction bottle and a solvent, adding a compound shown as a formula (2) and 4-formylphenylboronic acid, fully stirring and dissolving, adding catalysts [1, 1' -bis (diphenylphosphino) ferrocene ] palladium dichloride and tetrakis (triphenylphosphine) palladium, reacting for 24-48h at 90-110 ℃ under the protection of nitrogen, cooling, extracting, drying, standing, spin-drying, and finally separating and purifying by column chromatography to obtain the compound shown as the formula (3);

b. dissolving the compound shown in the formula (3) by using dichloromethane, then adding trifluoroacetic acid, stirring at room temperature overnight, and after the reaction is finished, carrying out suction filtration to obtain a light yellow solid, namely the organic ligand.

5. The method for preparing a carbon-carbon double bond bridged chiral porous organic polymer according to claim 4, wherein in the step a, the mass ratio of cesium carbonate to cesium fluoride is 3: 1, the mass ratio between the compound represented by the formula (2) and 4-formylphenylboronic acid is 1: 3, [1, 1' -bis (diphenylphosphino) ferrocene ] dichloropalladium and tetrakis (triphenylphosphine) palladium in a mass ratio of 1: 1; the mass ratio of cesium carbonate, [1, 1' -bis (diphenylphosphino) ferrocene ] dichloropalladium to the compound represented by the formula (2) is 3: 1 and 0.1: 1.

6. the method for preparing a C-C double bond bridged chiral porous organic polymer as claimed in claim 4, wherein in step a, after the reaction is finished, the reaction system is cooled to room temperature, dichloromethane is used for extracting the reaction system, the organic phase is sequentially washed with saturated saline solution, anhydrous sodium sulfate is added for drying, after standing for 6 hours, a proper amount of silica gel is added for vacuum spin drying, and a column chromatography is used for separating out a light yellow solid, namely the compound shown in formula (3); the mobile phase composition in the column chromatography is 12:1, a mixed solvent of dichloromethane and ethyl acetate.

7. The method for preparing a carbon-carbon double bond bridged chiral compound according to claim 4, wherein the step b comprises: dissolving the compound shown in the formula (3) by using dichloromethane, then adding trifluoroacetic acid, wherein the addition amount of the trifluoroacetic acid is 4mL/mmol of the compound shown in the formula (3), stirring at room temperature overnight, after the reaction is finished, adding dichloromethane, continuously stirring, washing away the trifluoroacetic acid, then standing, and performing suction filtration to obtain a light yellow solid, namely the organic ligand shown in the formula (1).

Technical Field

The invention belongs to the technical field of preparation of organic functional materials, and particularly relates to a preparation method of a carbon-carbon double bond bridged chiral porous organic polymer.

Background

Chirality is widely present in nature, and is embodied in that its mirror image cannot coincide with the original object. Molecules with different chiral configurations may vary widely in their biological activities. Chiral catalysis is an important method for obtaining a chiral pure compound, and thus development of a highly efficient chiral catalyst is required. Most of the reported chiral catalysts are homogeneous catalytic systems, and have the defects of difficult separation from a product system, difficult recovery and reuse and the like. Relatively speaking, the heterogeneous catalyst system not only has the advantages of easy separation and recovery, environmental friendliness and the like, but also can improve the selectivity of asymmetric catalysis by utilizing the asymmetry and the porous structure of the surface structure of the heterogeneous catalyst system.

The porous organic polymer is an emerging polymer with a porous structure, and has the advantages of stable structure, large specific surface area, relatively low density, excellent catalytic performance and excellent adsorption performance, and the development is rapid in recent years and the attention of more researchers is attracted. The porous organic polymer material can realize diversification of material structure and function by chemical modification of a construction element; the catalytic active site with the chiral structural unit is introduced into the porous organic polymer, so that the application of the material in the aspect of chiral catalysis can be realized. At present, most of the reported connecting units of the chiral porous organic polymer are imine bonds, acylhydrazone bonds and the like, and the chemical bonds have certain reversibility, so that the stability, the electronic delocalization and the like of the materials are influenced, and the application of the materials in the aspects of asymmetric catalysis and the like is further limited.

Porous organic polymers with sp2 carbon-carbon double bond bridges can exhibit higher stability and have better conjugation; however, no reports on chiral porous organic polymers bridged by carbon-carbon double bonds exist.

Disclosure of Invention

The invention aims to provide a preparation method of a carbon-carbon double bond bridged chiral porous organic polymer, which is simple and easy to operate, and the prepared chiral porous organic polymer has higher chemical stability and thermal stability on one hand and better conjugation property and electron delocalization on the other hand.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows: a preparation method of a carbon-carbon double bond bridged chiral porous organic polymer comprises the following steps:

a. synthesis of organic ligands: the organic ligand is (S) -4,4' - (2- (pyrrolidine-2-yl) -1H-benzo [ d ] imidazole-4, 7-diyl) benzaldehyde shown as a formula (1);

b. sequentially adding an organic ligand and 2,4, 6-tricyano-1, 3, 5-trimethylbenzene into a high-pressure reaction kettle containing N, N-dimethylformamide to dissolve to obtain a reaction solution; the mass ratio between the organic ligand and 2,4, 6-tricyano-1, 3, 5-trimethylbenzene is (1-2): 1; the adding amount of the N, N-dimethylformamide is 10-20mL/mmol2,4, 6-tricyano-1, 3, 5-trimethylbenzene;

c. adding piperidine into the reaction solution, dissolving, reacting at 90-180 ℃ for 48-120h, cooling to room temperature after the reaction is finished, centrifuging the reaction material, and collecting precipitate; the mass ratio between piperidine and 2,4, 6-tricyano-1, 3, 5-trimethylbenzene is (3-15): 1;

d. and c, washing the precipitate collected in the step c with methanol, acetone and dichloromethane respectively for three times to obtain yellow powder, namely the carbon-carbon double bond bridged chiral porous organic polymer.

Preferably, in step b, the mass ratio between the organic ligand and 2,4, 6-tricyano-1, 3, 5-trimethylbenzene is 1: 1.5; the amount of N, N-dimethylformamide added was 15mL/mmol2,4, 6-tricyano-1, 3, 5-trimethylbenzene.

Preferably, in step c, after dissolution, the mixture is reacted at a temperature of 150 ℃ for 72h, and the mass ratio between piperidine and 2,4, 6-tricyano-1, 3, 5-trimethylbenzene is 6: 1.

further, the specific steps of synthesizing the organic ligand are as follows:

a. weighing cesium carbonate and cesium fluoride in a reaction bottle, adding water to dissolve, adding toluene, removing air in the reaction bottle and a solvent, adding a compound shown as a formula (2) and 4-formylphenylboronic acid, fully stirring and dissolving, adding catalysts [1, 1' -bis (diphenylphosphino) ferrocene ] palladium dichloride and tetrakis (triphenylphosphine) palladium, reacting for 24-48h at 90-110 ℃ under the protection of nitrogen, cooling, extracting, drying, standing, spin-drying, and finally separating and purifying by column chromatography to obtain the compound shown as the formula (3);

b. dissolving the compound shown in the formula (3) by using dichloromethane, then adding trifluoroacetic acid, stirring at room temperature overnight, and after the reaction is finished, carrying out suction filtration to obtain a light yellow solid, namely the organic ligand.

Preferably, in step a, the mass ratio between cesium carbonate and cesium fluoride is 3: 1, the mass ratio between the compound represented by the formula (2) and 4-formylphenylboronic acid is 1: 3, [1, 1' -bis (diphenylphosphino) ferrocene ] dichloropalladium and tetrakis (triphenylphosphine) palladium in a mass ratio of 1: 1; the mass ratio of cesium carbonate, [1, 1' -bis (diphenylphosphino) ferrocene ] dichloropalladium to the compound represented by the formula (2) is 3: 1 and 0.1: 1.

preferably, in the step a, after the reaction is finished, cooling to room temperature, extracting the reaction system by using dichloromethane, washing an organic phase by using saturated saline solution in sequence, adding anhydrous sodium sulfate for drying, standing for 6 hours, adding a proper amount of silica gel for vacuum spin drying, and separating a light yellow solid by using a column chromatography to obtain the compound shown in the formula (3); the mobile phase composition in the column chromatography is 12:1, a mixed solvent of dichloromethane and ethyl acetate.

Preferably, step b specifically comprises: dissolving the compound shown in the formula (3) by using dichloromethane, then adding trifluoroacetic acid, wherein the addition amount of the trifluoroacetic acid is 4mL/mmol of the compound shown in the formula (3), stirring at room temperature overnight, after the reaction is finished, adding dichloromethane, continuously stirring, washing away the trifluoroacetic acid, then standing, and performing suction filtration to obtain a light yellow solid, namely the organic ligand shown in the formula (1).

Compared with the prior art, the preparation method for preparing the chiral porous organic polymer by adopting the novel chiral organic ligand based on carbon-carbon double bond bridging is simple and efficient, and is convenient to separate and purify; the chiral porous organic polymer prepared by the invention has larger specific surface area and regular pore channel structure, is beneficial to enhancing the adsorption effect on reactant molecules and the smooth frame entry and exit of substrates and products in asymmetric photocatalysis, and is beneficial to reacting the substrate molecules with the function frame, thereby improving the catalytic activity; the chiral porous organic polymer has higher chemical stability and thermal stability on one hand, and also has better conjugation property and electron delocalization on the other hand.

Drawings

FIG. 1 is a nuclear magnetic resonance spectrum of a compound represented by formula (3) synthesized in example one;

FIG. 2 is a nuclear magnetic resonance spectrum of the organic ligand synthesized in the first example;

FIG. 3 is a schematic structural framework of a chiral porous organic polymer prepared by an example;

FIG. 4 is an infrared spectrum of a chiral porous organic polymer synthesized in example one;

FIG. 5 is a solid nuclear magnetic diagram of a chiral porous organic polymer synthesized according to example one;

fig. 6 shows the nitrogen desorption isotherms and pore size distribution curves of the chiral porous organic polymer synthesized in example one, (a) shows the nitrogen desorption isotherms, and (b) shows the pore size distribution curves.

Detailed Description

The invention is described in further detail below with reference to the figures and specific examples.

The starting materials and reagents used in the following examples are all conventional commercial products unless otherwise specified.

Example one

A preparation method of a carbon-carbon double bond bridged chiral porous organic polymer comprises the following steps:

the synthesis steps of the organic ligand are as follows:

the synthesis of the compound represented by formula (2) is as follows:

Boc-L-proline (5.32g,24.72mmol) was added to a 100mL single-neck round-bottom flask, 60mL of anhydrous dichloromethane was measured to dissolve the Boc-L-proline, the mixture was cooled under ice bath conditions for 10min, ethyl chloroformate (2.28mL,23.32mmol) and anhydrous triethylamine (6.6mL,46.66mol) were added dropwise to the system, the reaction was continued for 10min with stirring, 3, 6-dibromo-1, 2-phenylenediamine (5.17g,19.44mmol) was then added to the reaction system in one portion, the reaction system was allowed to return to room temperature after stirring for 5min, and the reaction was continued for 36h, and the yellow turbid liquid slowly turned white. After the reaction, the mixture was extracted with dichloromethane and saturated aqueous NaCl solution, and the combined organic phases were dried by adding anhydrous sodium sulfate. The organic phase was then concentrated to a brown-yellow oil to which was added glacial acetic acid (25mL,0.44mmol) and reacted at 65 ℃ for 12 h. After the reaction is finished, saturated NaHCO is added₃Aqueous solution to make the reaction system alkaline, then extracting with ethyl acetate and saturated aqueous NaCl solution, then adding anhydrous Na₂SO₄Drying for 24 h. Adding silica gel, vacuum drying, and separating and purifying by column chromatography, wherein the polarity is approximately in dichloromethane: petroleum ether 2:1, and finally a white solid was obtained as the compound represented by formula (2) (5.6g,12.58mmol, yield 66%).

The synthesis of the compound represented by formula (3) is as follows:

into a 250mL two-necked round bottom flask was added cesium carbonate (6.76g,10.38mmol) and cesium fluoride (525.57mg,3.46mmol), which was dissolved ultrasonically with a small amount of water, followed by addition of 60mL toluene thereto, degassing for 2h (with N)₂Removing air from the reaction flask and solvent); in N₂Under the protection ofThe compound represented by the formula (2) (1.54g,3.46mmol) and 4-formylphenylboronic acid (1.56g,10.38mmol) were put into a reaction flask and dissolved, and tetrakis (triphenylphosphine) palladium (404.45mg,0.35mmol) and [1, 1' -bis (diphenylphosphino) ferrocene were added]Palladium dichloride (254mg,0.35mmol), N₂Replacing gas for 5 times, heating and refluxing the reaction system at 90 ℃ for 48h under the protection of nitrogen, extracting with dichloromethane after the reaction is finished, washing an organic phase with saturated saline solution, and drying with anhydrous sodium sulfate. The solvent was evaporated to dryness and separated by column chromatography (dichloromethane: ethyl acetate 12:1 ═ v: v) to give a pale yellow solid (1.2g, 70% yield).

By detecting a hydrogen spectrum of the compound represented by the formula (3), the spectrum is shown in fig. 1, and the analytical data is as follows:¹HNMR(400MHz,CDCl₃) δ 11.40(s,1H),10.09(s,2H),8.34(s,2H),8.02(d, J ═ 8.0Hz,4H),7.84(s,2H),7.54(d, J ═ 17.6Hz,2H), 5.19-5.11 (m,1H), 3.50-3.39 (m,2H),3.17(s,1H),2.22(d, J ═ 11.8Hz,2H), 2.07-1.97 (m,1H),1.57(d, J ═ 23.7Hz,9H) these parameters correspond to the chemical structure of the invented compounds.

The synthesis of the organic ligand represented by formula (1) is as follows:

a compound represented by the formula (3) was added to a single-neck flask, and dichloromethane was added to dissolve the compound, and then an appropriate amount of trifluoroacetic acid was added in an amount of 4mL/mmol of the compound represented by the formula (3). After the overnight reaction is finished by stirring at room temperature, adding dichloromethane, continuously stirring to wash out trifluoroacetic acid, standing, and performing suction filtration to obtain a light yellow solid, namely the compound organic ligand shown in the formula (1).

By detecting the hydrogen spectrum of the organic ligand, the spectrogram is shown in fig. 2, and the analytical data are as follows:¹HNMR(400MHz,DMSO-d₆) δ 13.01(s,1H),10.13(s,2H),9.83(s,1H),9.12(s,1H),8.43(s,2H),8.09(s,6H),7.66(d, J ═ 53.2Hz,2H),5.03(s,1H),3.48(d, J ═ 7.6Hz,1H),2.48(s,1H), 2.38-1.99 (m,3H) —. these parameters correspond to the chemical structure of the invented compounds.

Adding 198mg of organic ligand synthesized by the above process and 97.6mg of 2,4, 6-tricyano-1, 3, 5-trimethylbenzene into a high-pressure reaction kettle containing 5mLN, N-dimethylformamide in sequence to dissolve to obtain a reaction solution; the mass ratio between the organic ligand and 2,4, 6-tricyano-1, 3, 5-trimethylbenzene is 1: 1; the adding amount of the N, N-dimethylformamide is 10mL/mmol2,4, 6-tricyano-1, 3, 5-trimethylbenzene; adding 138 mu L of piperidine into the reaction solution, dissolving, reacting at 90 ℃ for 48h, cooling to room temperature after the reaction is finished, centrifuging the reaction material, and collecting precipitate; the mass ratio between piperidine and 2,4, 6-tricyano-1, 3, 5-trimethylbenzene is 3: 1; the collected precipitate was washed with methanol, acetone and dichloromethane three times, respectively, to obtain yellow powder, i.e., a carbon-carbon double bond bridged chiral porous organic polymer, with a yield of 70%, and a schematic structural framework diagram thereof is shown in fig. 3.

In order to verify the success of this example in synthesizing a new chiral porous organic polymer, infrared spectroscopy was performed on the chiral porous organic polymer obtained in this example. From FIG. 4, it can be seen that the wavelength is 1697cm^-1The position is the characteristic absorption of aldehyde group (-CHO) in the organic ligand, and after the chiral porous organic polymer is synthesized, 1697cm^-1The peak of aldehyde group absorption disappeared and was 2225cm^-1The cyano (-CN) group absorption was retained at 960cm^-1The characteristic absorption of the double bond after condensation is generated, which indicates the successful synthesis of the target chiral porous organic polymer.

Meanwhile, a solid carbon spectrum test is carried out on the chiral porous organic polymer, and the chiral porous organic polymer is subjected to C assignment, as shown in FIG. 5, which further proves that a new chiral porous organic polymer is successfully synthesized.

From the analysis of the nitrogen desorption diagram and the pore size distribution diagram in FIG. 6, the chiral porous organic polymer material has a typical microporous structure and a specific surface area of 525m²g^-1。

Example two

A preparation method of a carbon-carbon double bond bridged chiral porous organic polymer comprises the following steps:

adding 297mg of the organic ligand synthesized in the first example and 97.6mg of 2,4, 6-tricyano-1, 3, 5-trimethylbenzene into a reaction bottle containing 7mLN, N-dimethylformamide in sequence to dissolve the organic ligand and the 2,4, 6-tricyano-1, 3, 5-trimethylbenzene to obtain a reaction solution; the mass ratio between the organic ligand and 2,4, 6-tricyano-1, 3, 5-trimethylbenzene is 1.5: 1; the adding amount of the N, N-dimethylformamide is 15mL/mmol2,4, 6-tricyano-1, 3, 5-trimethylbenzene;

adding 276 mu L of piperidine into the reaction solution, reacting for 72h at the temperature of 150 ℃ after dissolving, cooling to room temperature after the reaction is finished, centrifuging the reaction material, and collecting precipitate; the mass ratio between piperidine and 2,4, 6-tricyano-1, 3, 5-trimethylbenzene is 6: 1;

the collected precipitate was washed with methanol, acetone and dichloromethane three times, respectively, to obtain a pale yellow powder, i.e., a carbon-carbon double bond bridged chiral porous organic polymer, with a yield of 85%, and a schematic structural framework diagram thereof is shown in fig. 3.

EXAMPLE III

A preparation method of a carbon-carbon double bond bridged chiral porous organic polymer comprises the following steps:

sequentially adding 395.5mg of the organic ligand synthesized in the first embodiment and 97.6mg of 2,4, 6-tricyano-1, 3, 5-trimethylbenzene into a reaction bottle containing 10mLN, N-dimethylformamide to dissolve to obtain a reaction solution; the mass ratio of the organic ligand to the 2,4, 6-tricyano-1, 3, 5-trimethylbenzene is 2: 1; the adding amount of the N, N-dimethylformamide is 20mL/mmol2,4, 6-tricyano-1, 3, 5-trimethylbenzene;

adding 742 mu L of piperidine into the reaction solution, dissolving, reacting at 180 ℃ for 120h, cooling to room temperature after the reaction is finished, centrifuging the reaction material, and collecting precipitate; the mass ratio between piperidine and 2,4, 6-tricyano-1, 3, 5-trimethylbenzene is 15: 1;

the collected precipitate was washed with methanol, acetone and dichloromethane three times, respectively, to obtain a pale yellow powder, i.e., a carbon-carbon double bond-bridged chiral porous organic polymer, with a yield of 80%, and a schematic structural framework diagram thereof is shown in fig. 3.

Example four

A preparation method of a carbon-carbon double bond bridged chiral porous organic polymer comprises the following steps:

adding 297mg of the organic ligand synthesized in the first example and 97.6mg of 2,4, 6-tricyano-1, 3, 5-trimethylbenzene into a reaction bottle containing 10mLN, N-dimethylformamide in sequence to dissolve the organic ligand and the 2,4, 6-tricyano-1, 3, 5-trimethylbenzene to obtain a reaction solution; the mass ratio between the organic ligand and 2,4, 6-tricyano-1, 3, 5-trimethylbenzene is 1.5: 1; the adding amount of the N, N-dimethylformamide is 20mL/mmol2,4, 6-tricyano-1, 3, 5-trimethylbenzene;

adding 276 mu L of piperidine into the reaction solution, reacting for 72h at the temperature of 150 ℃ after dissolving, cooling to room temperature after the reaction is finished, centrifuging the reaction material, and collecting precipitate; the mass ratio between piperidine and 2,4, 6-tricyano-1, 3, 5-trimethylbenzene is 6: 1;

the collected precipitate was washed with methanol, acetone and dichloromethane three times, respectively, to obtain a pale yellow powder, i.e., a carbon-carbon double bond bridged chiral porous organic polymer, with a yield of 85%, and a schematic structural framework diagram thereof is shown in fig. 3.